The cause of volcanic lightning is not
completely understood. Geologists assume that the cause is similar to
the cause of lightning in thunderstorms. From an electric universe point
of view, the Earth is a small charged body moving in a large cell of
plasma, and there is charge waiting for a connection to it.

More than 150 times in the past two centuries, volcanic eruptions have
been accompanied by spectacular displays of lightning. Sometimes broad
bolts of lightning streak across the sky. Other times St. Elmo's fire
(ball lightning) cascades from above. Sometimes volcanoes produce
branching displays such as at Sakurajima (see photo above.) The 1981
eruption of Mt St Helens featured a spectacular display of sheet
lightning, with truck-sized balls of St Elmo's fire seen rolling along
the ground 29 miles north of the mountain. Other well-known volcanoes
that produced lightning include Vesuvius (1944), Krakatau (1990's),
Surtsey, the new volcanic island in Iceland (1963), and Paracutin, the
cinder cone that grew out of a farmer's field in Mexico (1940's.)

The cause of volcanic lightning is not completely understood. Geologists
assume that the cause is similar to the cause of lightning in
thunderstorms, which is also not completely understood. [For discussion
of lightning, see TPOD Sept 17, 2004, Weather: Fair, Foul and Electric]
For years, geologists have talked about charge separation caused by
volcanic dust particles colliding and building up static charges.
Recently a new theory has been proposed that relies on the water content
of magma.

From an electric universe point of view, the Earth is a small charged
body moving in a large cell of plasma. Because of this, explanations of
all physical phenomena in, on, and near the Earth must take the
electrical behavior of plasma into account. The Physics of the Plasma
Universe by Anthony Peratt describes magma as a plasma, a medium
containing moving charges. So we should expect volcanoes not only to
exhibit electrical behavior but to have that behavior connected with the
larger plasma environment, that is, to be elements in a larger
electrical circuit.

But why do some volcanoes produce lightning while others don't? More
curious, why do some volcanoes with large dusty plumes produce little or
no lightning and others with small or mediocre plumes produce much
lightning? The simple answer could be that all volcanoes are electric
but that the lightning displays happen only when the resistance to the
volcanic current is high. You have a good example of this in your home.
The electric wires that carry the current from the wall socket to your
lamp don't produce heat or light. But when that same current encounters
the high resistance of a tungsten filament, it does produce heat and
light.

By studying the electrical component of volcanoes on Earth, plasma
geologists can gather clues about the mysteries of Earth's volcanic
geologic history. For example, it may help to explain why volcanism in
the past -- the great basalt floods -- was hotter and more voluminous
than in the present. And it may even help explain why Mars has volcanoes
that are many times larger than any found on Earth today. Were Earth and
Mars subjected to more powerful plasma interactions in the past?